SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bebec32ecf0cf706fd225e06a522748ff35def35559fd9ca17e9f165843f9986' 
  AND token = 'wVjt4f8IO2ilcrhYbQWi+uKMrgEND3wdL1Fwy/qjAYc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}